The present invention is directed generally to breastmilk pumps and, more particularly, to an improved breast pump assembly for expressing mothers' milk, which may be used in a manually-driven mode as well as a motor-driven mode.
Breast pumps for extracting or expressing breastmilk from a woman's breasts for later use by an infant have been available for years. Typically, these breast pumps include a funnel-shaped hood, or shield, that is placed over the nipple and a substantial portion of the breast. A reduced pressure or vacuum is intermittently generated in the hood in a manner which causes milk to be expressed from the breast within the hood. The milk then typically flows from the hood to a storage container for later use.
Generally, two types of breast pumps have been marketed for use by nursing women: motor-driven pumps; and manually-operated pumps. In manually-operated breast pumps, the intermittent suction action is typically generated by means of a compressible bulb or, more frequently, a piston-type pump. The piston pump generally includes a piston cylinder connected to the hood, and a piston slidably disposed within the piston cylinder and which is reciprocated by a hand-drivable piston rod. Motor-driven pumps typically either have a separate vacuum pump attached to the hood by tubing, or the motor is built into the hood assembly itself.
U.S. Pat. No. 5,007,899 discloses a drive unit to which the piston pump of an otherwise manually-operated breast pump can be attached for motorized breast pumping. The present invention is the particular result of improvements to the breast pump assembly disclosed in U.S. Pat. No. 5,007,899, and to the LACTINA breast pump assembly manufactured and sold by Medela, Inc. to which the foregoing patent relates.